Insecticide For Blackberries

1. Blackberries are perennial shrubs with woody, and often thorny, canes. They can reach heights up to 8 feet, but typically require some support from a trellis or other structure. Leaves have three to five fuzzy, green-gray, alternately arranged leaflets. Blackberry flowers are small and white, with five petals. They produce a cluster of edible, blue-black drupelets up to 1 inch long. The plant varieties favored specifically for their berries grow in U.S. Department of Agriculture plant hardiness zones 5 through 8.

Pest Insects

1. Several species of fruit-boring larvae, along with aphids, scales, mites and beetles are pests of blackberries. One insect of particular concern is the spotted-wing drosophila. Discovered in California in 2008, this fruit fly is native to Japan. Unlike other fruit flies, it feeds on both healthy and injured fruit. As it is a relatively new pest, knowledge of its prevention and treatment options are limited.

Natural Control

1. When plants are healthy, they are more capable of avoiding infestation and damage from insects. Irrigation, fertilizer applications and pruning, suitable to the variety of plant and the climate zone, all contribute to blackberry health. Natural predators, including ladybugs, lacewings and parasitic wasps, eliminate aphids, scales, mites and some larvae. Encourage these pest-eating bugs by avoiding unnecessary insecticide use. For fruit-boring insects, remove the damaged fruit and dispose of it in a sealed container to prevent reintroduction. Hand-remove larger visible pests such as beetles and caterpillars and drop them in soapy water.

Chemical Control

1. When natural methods fail and when other plants are in jeopardy from a spreading pest population, chemical control may be required. Insecticidal soaps and horticultural oils are effective against aphids and scales with little impact on the environment and beneficial insects. Insecticides containing spinosad treat spotted-wing drosophila but must be applied at night or early morning to prevent harming beneficial bees. Other, more potent chemicals such as malathion or carbaryl are available for blackberry pests, but are more suited to larger scale operations than a home garden.

   Every plant has the future potential for disease and insect damage. Factors such as location and weather will play a part in which issues your plants encounters. If available, disease-resistant varieties are the best option for easy care; and for all types of plants, proper maintenance (such as watering, pruning, spraying, weeding, and cleanup) can help keep most insects and diseases at bay.

   Crown Gall

   Plants appear stunted and slow growing; leaves may be reduced in size, little or no fruit. If plant is dead, inspect roots for hard, woody tumors. Note: many things can cause stunted plants.

   Control

   • Consult County Extension Agent

   Aphids

   They are the size of a pinhead and vary in color depending on the species. Cluster on stems and under leaves, sucking plant juices. Leaves then curl, thicken, yellow and die. Produce large amounts of a liquid waste called “honeydew”. Aphid sticky residue becomes a growth media for sooty mold.

   Natural Control

   • Monterey Fruit Tree Spray Plus

   Chemical Control

   • GardenTech® Sevin® Concentrate Bug Killer

   Cane Borer

   Adult is a long-horned beetle. Larvae indicated by sawdust.

   Natural Control

   • Remove and destroy infected canes.

   Other Control Options

   • Consult County Extension Agent

   Cane Blight

   Enters through wounds made by insects or mechanically. Cause large brown dead areas (cankers). Often first noticed when leaves wilt and wither. Cut back to below cankers; disinfect shears between cuts with 1 part bleach and 10 parts water. Dispose of pruning.

   Natural Control

   • Monterey Fruit Tree Spray Plus

   Spot Anthracnose

   It is most common on Black raspberry. Reddish-brown sunken spots with purple margins and light gray centers appear on young shoots. Grow together into cankers. Leaves may drop early. Fruit may dry up. Over winters in lesions on old canes. Proper pruning can help control. Always remove and burn old fruiting canes after harvest.

   Control

   • Consult County Extension Agent

   Orange Rust

   Not common on Red raspberry but serious on all others, especially Blackberries. Underside of leaves covered with orange-yellow spores. Remove infected plants.

   Natural Control

   • Monterey Fruit Tree Spray Plus

   Fruit Rot

   Appears as gray, hairy mold on decays blossoms, green and ripening fruits and harvested fruits.

   Control

   • Contact County Extension Agent

   Powdery Mildew

   Whitish-gray powdery mold or felt like patches on buds, young leaves and twigs. Leaves may crinkle and curl upward. Over winters in fallen leaves.

   Natural Control

   • Clean up fallen leaves and other debris.
   • Monterey Fruit Tree Spray Plus

   Fruitworm (Sawfly)

   Adult is yellow to brown sawfly beetle, 1/4” long. Larvae are brown and white, 1/8” long. Adults make slits in flower buds and larvae feed on berries.

   Natural Control

   • Hi-Yield® Vegetable & Ornamental Insect Control

   Chemical Control

   • GardenTech® Sevin® Concentrate Bug Killer

   Mites

   Pinpoint size, many different colors. Found on undersides of leaves. Severe infestations have some silken webbing. Sap feeding causes bronzing of leaves.

   Natural Control

   • Monterey Fruit Tree Spray Plus

   Chemical Control

   • GardenTech® Sevin® Concentrate Bug Killer

   Japanese Beetle

   Adult is metallic green beetle, which skeletonizes leaves. Larvae are a grub, which feeds on turf roots. Check turf product labels for timing of control of grubs. This is more of this problem is east of the Mississippi River.

   Natural Control

   • Traps

   Chemical Control

   • GardenTech® Sevin® Concentrate Bug Killer

   Leafroller

   Pale yellow or ‘dirty’ green worms. Leaves are rolled and webbed together where insects feed. Eventually becomes skeletonized.

   Natural Control

   • Hi-Yield® Vegetable & Ornamental Insect Control
   • Natural Guard® Caterpillar Killer Spray w/BT

   Chemical Control

   • GardenTech® Sevin® Concentrate Bug Killer